Course this can easily backfire. The time limit causes them to try and push out more than normal, inflating prices because the demand goes up with the limited time frame. You have it even worse. You do a search for an item that you've been looking for. Find it being Vended. Yes it appears Over Priced. You go to the store and cannot find it with its last location. Search again and the store is now gone because they timed out of their Vending.
I can see a good number actually stop autovending and trying more direct means of sales. Like through the forums or by spamming Main and private channels. This is to say that they don't just stop. Seeing as they'd prolly focus more onto less accounts to better keep track of who is vending, where, when and how much time they have left.
Just by adding more work to a very, VERY simple process, we risk of having the opposite effect than what we desire. It COULD still curve the economy in a different way, but as far as I can see, I cannot tell if it would be beneficial or detrimental.
